Patent Application
20150372537
The present disclosure relates to systems and methods for preventing electric power converters from operating in sleep mode.
This section provides background information related to the present disclosure which is not necessarily prior art.
Electric power systems sometimes include a primary power source and a backup power source for providing backup power to an electric load when the primary power source is removed and/or unable to satisfy load requirements due to, for example, a loss of input power, malfunction, etc. It is desirable for the backup power source to provide its power to the load as quickly as possible after the primary power source falters.
Commonly, the backup power source includes an output converter for regulating the output of the backup power source. Typically, the output converter enters a sleep mode (e.g., a standby mode, etc.) to conserve power, improve efficiency in the system, etc. when the backup power source is not needed. For example, the output converter may operate in its sleep mode by employing pulse skipping control, etc.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
According to one aspect of the present disclosure, a system for providing power to a load includes an output converter configured to provide power to a load, at least one battery coupled to the output converter, an input converter coupled to the at least one battery and the output converter, and a control circuit coupled to the input converter. The input converter is configured to provide an output voltage and an output current to the at least one battery and the output converter. The control circuit is configured to regulate the output voltage of the input converter at a defined voltage level to prevent the output converter from operating in a sleep mode.
According to another aspect of the present disclosure, a control circuit for a battery backup unit (BBU) configured to provide power to a load is disclosed. The BBU includes an output converter configured to provide power to a load, at least one battery coupled to the output converter, and an input converter coupled to the at least one battery and the output converter. The input converter is configured to provide an output voltage and an output current to the at least one battery and the output converter. The control circuit is configured to couple to the input converter and regulate the output voltage of the input converter at a defined voltage level to prevent the output converter from operating in a sleep mode.
Further aspects and areas of applicability will become apparent from the description provided herein. It should be understood that various aspects of this disclosure may be implemented individually or in combination with one or more other aspects. It should also be understood that the description and specific examples herein are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts or features throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
A system for providing power to a load according to one example embodiment of the present disclosure is illustrated in
By employing the systems disclosed herein, converters may be maintained in an active mode, and thus in a ready state and not a sleep mode (sometimes referred to as a standby mode, etc.). As a result, when an output converter (e.g., the output converter 106) is required to provide power to a load, the converter can provide a desired regulated voltage to the load more quickly than if the converter was in a sleep mode or the like.
For example, the output converter 106 of
However, if the converter 106 receives a small amount of voltage from the converter 102 and/or the battery 104, the converter 106 may pass a small amount of current to its output (e.g., which may be lost through heat dissipation, etc.). As a result, the converter 106 may be prevented from operating in its sleep mode. As such, the converter 106 may be able to more rapidly provide its full load output to sustain the load because the converter remains in its active mode (e.g., a mode of operation where the converter provides at least some power), has a smaller load current step (e.g., from the small amount of current to full load), etc.
For example, the output converter 106 (and/or other output converters disclosed herein) may include an output capacitor (not shown) that may discharge (e.g., at least partially discharge) if the output converter 106 enters a sleep mode. In such cases, the output capacitor may be required to charge before the output converter 106 can regulate its output voltage at the desired regulated voltage. However, if the output converter 106 is prevented from entering a sleep mode (as explained herein), the output capacitor may remain charged. As such, the output converter 106 can regulate its output voltage at the desired regulated voltage without having to charge the output capacitor. As a result, the output converter 106 may provide the desired regulated voltage quickly enough to sustain the load.
As explained above, the control circuit 108 of
In some embodiments, the defined voltage level may be stored in memory of the system 100 (e.g., in the control circuit 108), determined based on one or more sensed parameters in the system 100, etc. In some examples, the defined voltage level may adjust from one level to another level based on sensed parameters, etc.
In some embodiments, the control circuit 108 may optionally monitor an input current (Iinb) to the battery 104, and in response to this input current (Iinb) equaling a defined current level, regulate the output voltage (Vout) of the input converter 102 at the defined voltage level as explained above. If the input current (Iinb) does not equal (e.g., the current (Iinb) is greater than the defined current level), the control circuit 108 may regulate the output voltage (Vout) of the input converter 102 at a different voltage level (e.g., a voltage higher than the defined voltage level).
For example, and as shown in
The defined current level may be any suitable current level. In some examples, the defined current level may be greater than zero. For example, the defined current level may be near zero. In some embodiments, the defined current level may be less than or equal to about one tenth percent ( 1/10%) of an output current of the output converter 106. For example, if the output current is 100 amperes, the defined current level may be about 0.1 amperes or less.
Additionally and/or alternatively, the control circuit 108 may determine a charge state (e.g., sometimes referred to as a state of charge) of the battery 104, and in response to the battery 104 having available capacity, decrease the output voltage (Vout) of the input converter 102 to the defined voltage level. In some examples, the control circuit 108 may decrease the voltage (Vout) of the input converter 102 to the defined voltage level when the battery 104 is in its substantially charged state. In such examples, the control circuit 108 may regulate the output voltage (Vout) of the input converter 102 at the defined voltage level to maintain the battery 104 in its substantially charged state.
The control circuit 108 may determine a charge state of the battery 104 in any suitable manner including, for example, by monitoring one or more parameters in the system. In such examples, the control circuit 108 can calculate a charge state of the battery 104 based on these parameters, set parameters, etc. In other embodiments, the control circuit 108 may receive a signal from the battery 104 indicative of a charge state.
For example,
Once the control circuit 208 determines the battery 104 has available capacity (e.g., is charged, etc.), the control circuit 208 can regulate the voltage (Vout) of the input converter 102 at the defined voltage level. Thus, if energy is available from the input converter 102 (e.g., the input converter 102 is able to provide its voltage (Vout) as explained above, etc.) and/or the battery 104 has available capacity, the control circuit 208 may sense one or both conditions and keep the output converter 106 active as explained above.
For example, the input converter 102 can provide a voltage (Vout) sufficient to charge the battery 104. This voltage may be higher than the defined voltage level. When the control circuit 208 determines the battery 104 is charged, the control circuit 208 can decrease the voltage (Vout) to the defined voltage level and then regulate the voltage (Vout) at the defined voltage level as explained above.
In some examples, decreasing the voltage (Vout) causes the battery input current (Iinb) to decrease. In such examples, once the battery input current (Iinb) reaches the defined current level (e.g., substantially zero, etc.), the control circuit 208 can regulate the voltage (Vout) at the defined voltage level as explained above. Thus, although the battery input current (Iinb) may be substantially zero, the output converter 106 may continue to receive a small amount of current (e.g., Iout-Iinb) from the input converter 102.
Additionally, because the output voltage (Vout) is regulated when the input current (Iinb) to the battery 104 is substantially zero, the system 100 (and other systems including the features disclosed herein) may substantially avoid providing a trickle charge to the battery 104 when the battery is in its fully charged state.
In other embodiments, the control circuit 108 may also control the output converter 106. For example,
Additionally, although
In some embodiments, the batteries and/or one or both converters disclosed herein may be components of a battery backup unit (BBU) for providing power to a load as explained above. For example,
The converter 402, the batteries 404, and the converter 406 may be substantially similar to the input converter 102, the battery 104, and output converter 106, respectively, of
Further, although not shown, the system 400 of
Additionally, the input converters and/or the output converters may include one or more power switches. For example, and as shown in
In some examples, a system may include multiple BBUs with one or more of the BBUs including an output converter that is prevented from operating in its sleep mode as explained above. For example,
The input converters and/or the output converter disclosed herein may include any suitable converter(s). For example, and as further explained below, the input converters may include a DC/DC converter, an AC/DC converter (e.g., commonly referred to a rectifier), etc. and the output converters may include a DC/DC converter, a DC/AC inverter (e.g., if AC power is desired), etc. The input converters and/or the output converter may have any suitable topology (e.g., a buck converter, boost converter, bridge converters, etc.) and, in some cases, be part of a power supply (e.g., switched mode power supply, etc.).
The batteries disclosed herein may be any suitable number and type of rechargeable battery including, for example, a lithium ion (Li-ion) battery, a nickel metal hydride (NiMH) battery, a nickel cadmium (NiCd) battery, etc. In some embodiments, all of the batteries in a system may include the same type of rechargeable battery. For example, all of the batteries in a system may include Li-Ion batteries. In other embodiments, some of the batteries in a system may be one type of rechargeable batteries (e.g., Li-Ion batteries, etc.) and other batteries in the system may be another type of rechargeable batteries (e.g., NiCd batteries, etc.).
Additionally, the example systems disclosed herein may be employed in any suitable application including, for example, DC power applications and/or AC power applications. For example, the example systems may be used in telecommunication applications, information technology applications, etc. In some embodiments, the systems may be employed in electronic equipment enclosures (e.g., data racks, server cabinets, etc.) including, for example, stationary and/or modular enclosures.
Further, the systems may provide any suitable output power including, for example, AC power and/or DC power. In some embodiments, the systems may provide 5 VDC, 12 VDC, 24 VDC, 48 VDC, 400 VDC, 120 VAC, etc.
The control circuits disclosed herein may include an analog control circuit, a digital control circuit (e.g., a digital signal processor (DSP), a microprocessor, a microcontroller, etc.), or a hybrid control circuit (e.g., a digital control circuit and an analog control circuit). Thus, the methods disclosed herein may be performed by a digital controller. Further, one or more portions of the control circuit may be an integrated circuit (IC).
Additionally, the control circuits may be a portion of a system control circuit (e.g., a system control card (SCC), etc.) for a system including a battery pack, an input converter, and/or an output converter. Alternatively, the control circuits may be a dedicated control circuit for one battery pack, one input converter, and/or one output converter if desired. If the battery pack, the input converter, and/or the output converter are components of a BBU as explained above, the control circuits may be an external control circuit (e.g., a system control circuit external the BBU, etc.), an internal control circuit within the BBU, etc.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
This application claims the benefit of U.S. Provisional Application No. 62/013,798 filed Jun. 18, 2014. The entire disclosure of the above application is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62013798 | Jun 2014 | US |
